A cylindrical ThermoPhotoVoltaic (TPV) generator may use combustion to heat a cylindrical tube to a temperature in the range of 1200° C. to 1500° C. as we have previously described. This glowing tube then emits infrared radiant energy. An array of low bandgap photovoltaic (PV) cells surrounds this glowing emitter, receives the infrared radiant energy, and converts it to electricity. This cylindrical TPV generator was also equipped with a recuperator used to recycle heat from the combustion exhaust stream back into the combustion air for a higher efficiency TPV generator. These cylindrical TPV generators can potentially be used to generate heat and power for the home with 90% fuel utilization efficiency.
We have described an AntiReflection coated Refractory Metal (AR/RM) IR emitter designed to emit infrared energy primarily in a wavelength band that the PV cells can convert. However, many of these AR/RM emitters cannot be operated in air because of oxidation of the refractory metal. In our specific TPV systems, we use GaSb PV cells that respond to IR wavelengths out to 1.8 microns and AR coated tungsten foil as the key emitter and receiver components. We have noted that various other material combinations are possible as long as they operate in this IR wavelength range.